Without wanting to get too far into the weeds, I think asking 'what am I crap at?' is the wrong question, because it's trying to define the wrong problem.
Assuming the goal is 'to successfully climb route y or boulder x'*, then the problem isn't 'being crap' at something. The problem is 'failing on route y or boulder x'.
This is because you can be crap, relative to peers and according to the wisdom of a benchmarking model, while still being skin-of-your teeth good enough to get up your goal routes and boulders.
I say this because of the truth staring us in the face of the many outliers to the received wisdom of models, some of them mentioned on here.. It's clearly true that you don't need to be getting PBs on training goals or achieve someone else's training benchmark to climb well enough to achieve goal climbs. There are endless examples in climbing of people whose finger strength isn't as high as it could be but who climb much harder than they 'should' according to a model, and endless examples of people with very good finger strength who don't achieve success on the routes they 'should' according to a model.
I do think part of the appeal of a model - Lattice is a well known one - is it enables a game of peer comparison like social media (which appeals to most of us) where you can compare your finger strength, fitness etc. to other people and against standard benchmarks. You also get the little badge of achievement thing of getting a 'rating' of what grade you're theoretically capable of. We all love a test to see how we compare to others. But it isn't especially meaningful for the goal of getting up climbs.
Whereas focussing on the immediate reason why you failed on the goal route/boulder can, if you're honest and analytical, and have some experience of seeing other climbers doing similar routes, be black and white. With a bit of experience it's not as hard as you think to understand why you failed.
Also, trying to work out 'what am I crap at' is always going to be a nebulous, relative concept - who are you comparing to, and where on the scale does 'crap' become 'good'? It doesn't really work. We're all 'crap' compared to some and good compared to others. Which is why people came up with supposed objective models..
I notice you're only talking about bouldering. I think perhaps with bouldering getting really strong fingers will overcome a lot of other possible reasons for failure, and having strong finger will mask other potential reasons for failure more than in route climbing. I think routes overall require more overall ingredients for success, and steely fingers won't get you as far before some other reason rears it's head to make you fail.
* It's a good question to ask if the end goal is to have good all-round balanced levels of strength, fitness and flexibility. What you then do with that potential is more difficult to predict.
